1. Field
The invention is in the filed of self-contained cooling devices formed within or adapted to be inserted within a beverage or food container for cooling the contents of the container.
2. State of the Art
Because of the custom of drinking mass quantities of cold liquids in our present society, great expense and effort is exerted in cooling and maintaining beverages in a cool state. In situations where it is impractical to carry modern refrigeration equipment, it is necessary to use ice, other similar materials, or insulated containers to maintain beverages in a cool state. However, ice and similar material only last for relatively short periods of time and must be continuously replenished. Similarly, insulated containers only maintain their contents cool for a similar relatively short period. In many instances when a cold beverage is desired, if an already cold beverage is not on hand and it is not desired to dilute the beverage by the addition of ice cubes, it is impractical to chill a warm beverage because normal refrigeration units or so-called "ice chests" require time to permit the convection cooling process to fully chill the beverage to a suitable temperature. It is thus desirable to have a beverage or other food container with a self-contained cooling device therein that can rapidly chill the container contents when desired without the need for external refrigeration units or "ice chests".
Various attempts have been made to provide cooling devices within a food container. Such devices have generally used a chemical reaction or an expanding gas to provide the required cooling. However, most of these previous attempts at self-cooling containers have resulted in devices that are formed as part of the container itself, requiring that special containers be made to accommodate the cooling devices. This necessitates a totally new design for such a container, and, usually a new design for the canning machinery that is used to fill and seal such containers. Examples of such designs are shown in U.S. Pat. Nos. 3,597,937; 3,309,890; 3,636,726; 3,987,643; 3,525,236; 3,319,464, 3,379,025; 3,726,106; and 3,320,767.
Several prior art devices, such as those shown in U.S. Pat. Nos. 3,919,856; 3,269,141; and 3,494,143 are secured merely to one end of a can. However these require a special, extensively modified can end in addition to the end having the normal beverage despensing opening and thus is not compatible with current beverage cans or beverage canning equipment.
In addition to not being compatable with existing cans and canning equipment, most of the prior art designs do not appear to be economical to manufacture and thus, could not be made and installed in a can at a cost which consumers would pay for the convenience of being able to quickly cool a drink at any location. The need remains for a practical and economical, self-contained cooling device that can be used with currently used cans, requiring only minor modification to such cans, and that can be installed in such cans using the present high speed canning equipment.